blending thermosensitive polymers with ph sensitive polymers for drug delivery and polymer chemistry

i am interested in discussing about the pros and cons of having a vesicle of ph sensitive polymer (with drug to be delivered inside it), inside a vesicle of thermosensitive polymer for drug delivery. This gives us dual control capabilities that is temperature and ph based trigger mechanism.things i need to know about this are

1. is this method a novel approach for drug delivery, for a disease which needs a local site and ph change for drug release.

2. the ph sensitive polymer works based on feedback approach like the release of drug is based on ph change in the system.external triggering is involved for temperature change.

3. what are the difficulties in design of such drug delivery approach.

4. can i use this method specifically for some disease preferably(like some particular cancer demanding temperature and ph conditions) ?

thank you all.